It is often desirable to interconnect circuits between two adjacent circuit-bearing substrate that are placed edge to edge with circuit termini adjacent the respective edges. In many applications the circuits on the respective substrates or circuit boards are formed in dense arrays with the typical pitch between adjacent contact pads being approximately one millimeter. The corresponding contacts in a connector, therefore, are relatively thin and are on the order of 0.1 to 0.5 millimeters. Thus, it is necessary to precisely align the circuit pads onto substrates with each other in at least one horizontal direction. The substrates, however, while being aligned in a first horizontal direction such that corresponding circuit termini are across from one another, may be slightly spaced from each other in a second horizontal direction of a plane and furthermore may also be spaced slightly vertically from one another owing to differences in thicknesses of the boards as well as positions within the electronic equipment in which the boards are used.
U.S. Pat. No. 5,263,868 discloses a flexible circuit interface for co-planar printed circuit boards. The connector includes a support housing and a flexible jumper circuit for bridging the printed circuit boards that abut each other. The flexible circuit includes an elastomeric member that can bridge the interface between the co-planar boards. To maintain the desired normal force of the connector over time, it is desirable that the elastomeric member be supported by a continuous surface, rather than by surfaces spaced by a gap or step. Additionally, the resiliency of the elastomeric member can be affected over time by changes in the environment, such as temperature variations, and when subject to continual vibrations or the like.
It is desirable, therefore, that the electrical connector be able to interconnect corresponding circuit termini on the boards while accommodating slight differences in horizontal and vertical arrangements of the substrates. The connector, therefore, needs to be able to interconnect corresponding circuit termini across a gap as well as up a step and to maintain the desired normal force on the circuit termini over time, even when subject to changes in temperature and vibrations.